In occasion such as speech/lecture where there are a lot of audiences, a speaker usually needs to project the content of the speech/lecture on a screen or present it on a blackboard. Moreover, the speaker also needs a pointing device to point at the content of the speech/lecture and draw the audience's attention.
Laser-pointing devices have been invented to assist speakers to point at content of a speech/lecture. A laser pointer is a common laser-pointing device. A laser pointer has an outer appearance of a ball-point pen. A light-emitting diode is provided on the laser pointer. When electricity is supplied, the light-emitting diode will emit light, such as a red pointing beam from a front end of the laser pointer. A speaker can point the content of the speech/lecture to the attention of the audience.
However, the pointing mode of the currently existing laser-pointing device is rather simple. The pointing mode of a laser pointer is usually a single dot of light. When a speaker needs to point at a content that covers a region, the speaker usually needs to continuously move the laser-pointing device. This is inconvenient to the speaker. Since the dot of light would disappear immediately, the pointing effect is quite limited.